Field of the Invention
The present invention relates to a maintenance support system, a maintenance support apparatus and a maintenance support method which support maintenance of a process control system built in a plant, a factory or the like.
Priority is claimed on Japanese Patent Application No. 2012-191351, filed on Aug. 31, 2012, the contents of which are incorporated herein by reference.
Background Art
Conventionally, a process control system for controlling various state amounts (e.g., pressure, temperature, and flow amount) in an industrial process is built in a plant, a factory or the like (hereinafter collectively referred to simply as a “plant”), and advanced automatic operation is implemented. In this process control system, a site device (a measuring device or a manipulation device) generally called a field device, and a controller which controls the site device are connected through a communication means. The controller collects process values (e.g., measurement values of the pressure, the temperature, the flow amount and the like) obtained in the field device, and manipulates (controls) the field device according to the collected process values. Accordingly, the process control system performs control of various state amounts.
In most conventional process control systems, a field device having an analog communication function and a controller are connected in a one-to-one correspondence relationship via an analog transmission line (e.g., a transmission line used for transmission of a “4 to 20 mA” signal). On the other hand, in a recent process control system, a digitized field device and a controller are often connected via a wired or wireless network (e.g., a field network) in order to realize an enhanced function.
Design, construction, and maintenance of such a process control system are generally performed by many engineers. For example, design of an operating scheme of the process control system is performed by a plant engineer. Creation of a specification of the process control system implementing the designed operating scheme is performed by a system engineer. Further, the construction and the maintenance of the process control system are performed by cooperation of site engineers and system engineers in charge of respective components (e.g., the field device, the controller, the network, and various programs used in the process control system) of the process control system.
In Japanese U.S. Pat. No. 3,445,470, Japanese U.S. Pat. No. 4,074,344, and Japanese U.S. Pat. No. 2,859,407, technologies for supporting maintenance and management of a plant or a process control system are disclosed. Specifically, in U.S. Pat. No. 3,445,470, technology for storing information on a remodeling construction of a plant facility in a computer device and managing an implementation status of the remodeling construction related to the plant facilities is disclosed. In U.S. Pat. No. 4,074,344, technology for automatically creating management drawings representing an interconnection between elements of a plant from a point connection and a control language script of a process control system is disclosed. In U.S. Pat. No. 2,859,407, technology for organically connecting a plurality of systems built in a plant and supporting reasonable maintenance and management under unified information management is disclosed.
From the viewpoint of effective utilization of facilities, a plant is required to be able to flexibly cope with a change in products and a production amount and safely work for a long period of time (e.g., 30 years or more). Similarly, a process control system built in the plant is required to be able to flexibly cope with a change in products and a production amount and operate for a long period of time equal to or longer than a working period of the plant.
In a process control system whose flexible operation is performed for a long period of time, a change in components constituting the process control system frequently occurs due to deterioration of facilities provided in a plant, a change in processes and materials, enhancement of efficiency or the like. The maintenance of the process control system is performed through cooperation between the site engineer and the system engineer, as described above. Therefore, when components constituting the process control system are changed, a task of changing contents of the specification is first performed by the system engineer. Then, a task (e.g., exchange or adjustment of field devices or the like) according to the changed contents of the specification is performed by the site engineer.
Thus, in the process control system, the components are changed based on the contents of the specification. Therefore, the process control system is basically configured according to the contents of the specification. However, an actual condition (actual configuration or actual settings) of the process control system may not necessarily conform to the contents of the specification but may deviate from the contents of the specification. This is because there is a case in which communication is not sufficiently performed between the system engineer performing a task of changing the contents of the specification and the site engineer performing the task according to the contents of the specification (or a case in which it is unnecessary to sufficiently perform the communication).
For example, in a recent process control system in which a field device and a controller are connected over a network, an operation can be performed if the field device is connected to the network. Therefore, a position of the connection of the field device to the network may not be so important. In this case, even when a site engineer connects the field device to a position different from that in the specification, the process control system works without problems. Therefore, the fact that a task different from the contents of the specification has been performed is not sent from the site engineer to a system engineer and accordingly a difference between the contents of the specification and the actual condition for the process control system is generated.
Here, even when the actual condition for the process control system deviates slightly from the contents of the specification, the process control system works normally, and problems are considered to rarely occur if components are not changed. However, when flexible operation is performed for a long period of time and a change in components is frequently performed, a difference between the actual condition for the process control system and the contents of the specification is considered to gradually increase.
Further, in a process control system whose operation is performed for a long period of time, an engineer involved in maintenance may be changed. Therefore, an actual condition for the process control system is also likely not to be recognized from the contents of the specification. When the actual condition for the process control system cannot be recognized from the contents of the specification, it is necessary to perform a confirmation task for confirming the actual condition, and a maintenance task takes much time. Further, when remodeling or updating of the process control system is performed, there may be a difference between a situation and the contents of the specification and accordingly it is necessary to perform the above confirmation task prior to the remodeling or updating.